Superionic Conduction using Ion Aggregates

  • Maranas, Janna Kay (PI)

Project: Research project

Project Details

Description

In today's energy climate, developing alternatives to gasoline for the transportation industry is critical. The batteries in today's fully electric and hybrid electric vehicles (Li ion battery) led to fires in computers and airplanes. Substitution of liquid electrolytes with polymer electrolytes can open the door to safer batteries that can get more miles (500 compared to 100) per charge. In order for this to occur, the speed with which Li ions move needs to increase by a factor of 100. This is a large increase, and can only be realized by completely changing the way in which these ions move. Currently, ions move through the polymer electrolyte by leaping from one polymer configuration to another, a method in which Li motion is coupled to polymer motion. This project goal is to design an electrolyte in which ions form a large network capable of conduction without the need for the polymer movement. Focus will be on Na ion batteries, rather than Li ion batteries, because Na is cheaper and more abundant than Li, as Li reserves are primarily located in South American.Three systems will be investigated: one in which the negatively charged ions are on the polymer backbone, one with linker ions to promote network formation, and one in which the negatively charged ions are on one polymer and the positively charged ions are on another polymer.It is recognized that simply increasing the ion content in ionomers does not provide a great amount of control over shape of the aggregates. Physical models of ion aggregates derived from our previous simulations suggest that ion aggregate sizes will be exponentially distributed in simple ionomer systems. In the first, we have prior data in which ions form linear chains, but not a network. Simply increasing ion content may be sufficient to form a conducting ion network. In the second, we can use terminating ions and linking ions to control the characteristics of the network. The third system may allow to probe ion contents greater than those allowed by the other two systems. We will apply our expertise in neutron scattering techniques, dielectric spectroscopy, and molecular dynamics simulations in order to provide a complete picture of the dual benefits of ionic aggregation. Observables from experimental techniques will be used to calibrate simulations, which then provide the detailed mechanistic information to improve future generations of these materials. At the conclusion of the project, we will demonstrate that a new variable for promoting conductivity - collective motion - that can be tuned through precisely tuned ion aggregation. We will show how ion aggregation can be controlled through ion content and ion identity. We will also introduce a new experimental system, PEO-swollen mixed polycation-polyanion electrolytes, which will primarily conduct through ion aggregates.
StatusFinished
Effective start/end date8/1/157/31/18

Funding

  • Basic Energy Sciences: $600,000.00

Fingerprint

Explore the research topics touched on by this project. These labels are generated based on the underlying awards/grants. Together they form a unique fingerprint.